Report on Lokon-Empung (Indonesia) — 8 February-14 February 2012
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 8 February-14 February 2012
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2012. Report on Lokon-Empung (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 8 February-14 February 2012. Smithsonian Institution and US Geological Survey.
1.358°N, 124.792°E; summit elev. 1580 m
All times are local (unless otherwise noted)
According to news articles, an explosion from the Tompaluan crater, in the saddle between the Lokon-Empung peaks, produced an ash plume that rose as high as 2 km above the crater on 10 February; loud "thumping" noises were also heard. Based on information from CVGHM, the Darwin VAAC reported ash plumes that rose to altitudes of 3-3.4 km (10,000-11,000 ft) a.s.l. during 10-12 February, though clouds prevented the detection of ash in satellite imagery.
Geologic Background. The twin volcanoes Lokon and Empung, rising about 800 m above the plain of Tondano, are among the most active volcanoes of Sulawesi. Lokon, the higher of the two peaks (whose summits are only 2 km apart), has a flat, craterless top. The morphologically younger Empung volcano to the NE has a 400-m-wide, 150-m-deep crater that erupted last in the 18th century, but all subsequent eruptions have originated from Tompaluan, a 150 x 250 m wide double crater situated in the saddle between the two peaks. Historical eruptions have primarily produced small-to-moderate ash plumes that have occasionally damaged croplands and houses, but lava-dome growth and pyroclastic flows have also occurred. A ridge extending WNW from Lokon includes Tatawiran and Tetempangan peak, 3 km away.